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<head><meta charset="utf-8"><title>meeting 2021-04-13 · wg-traits · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/index.html">wg-traits</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html">meeting 2021-04-13</a></h3>

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<a name="234390468"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234390468" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234390468">(Apr 13 2021 at 19:56)</a>:</h4>
<p>Howdy <span class="user-group-mention" data-user-group-id="692">@WG-traits</span></p>



<a name="234390487"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234390487" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234390487">(Apr 13 2021 at 19:56)</a>:</h4>
<p>Meeting in 4ish minutes</p>



<a name="234391264"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391264" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391264">(Apr 13 2021 at 20:01)</a>:</h4>
<p>Okay meeting time <span class="user-group-mention" data-user-group-id="692">@WG-traits</span></p>



<a name="234391292"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391292" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391292">(Apr 13 2021 at 20:01)</a>:</h4>
<p><span aria-label="wave" class="emoji emoji-1f44b" role="img" title="wave">:wave:</span></p>



<a name="234391344"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391344" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391344">(Apr 13 2021 at 20:01)</a>:</h4>
<p>howdy</p>



<a name="234391458"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391458" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391458">(Apr 13 2021 at 20:02)</a>:</h4>
<p>How is everyone?</p>



<a name="234391555"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391555" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391555">(Apr 13 2021 at 20:02)</a>:</h4>
<p>Any announcements?</p>



<a name="234391595"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391595" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391595">(Apr 13 2021 at 20:02)</a>:</h4>
<p>doing reasonably well</p>



<a name="234391641"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391641" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391641">(Apr 13 2021 at 20:03)</a>:</h4>
<p>tomorrow <span class="user-mention" data-user-id="125294">@Aaron Hill</span> and I are supposed to talk about their PR</p>



<a name="234391674"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391674" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391674">(Apr 13 2021 at 20:03)</a>:</h4>
<p>in the "office hour" time</p>



<a name="234391710"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391710" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391710">(Apr 13 2021 at 20:03)</a>:</h4>
<p>Great, but I think I've seen enough HList/Combine/Product traits for the day</p>



<a name="234391732"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391732" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391732">(Apr 13 2021 at 20:03)</a>:</h4>
<p>Which PR?</p>



<a name="234391765"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391765" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391765">(Apr 13 2021 at 20:03)</a>:</h4>
<p>No PR yet, but the opaque type problem from RA</p>



<a name="234391779"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391779" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391779">(Apr 13 2021 at 20:04)</a>:</h4>
<p><a href="https://github.com/rust-lang/chalk/issues/700">chalk#700</a></p>



<a name="234391866"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391866" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391866">(Apr 13 2021 at 20:04)</a>:</h4>
<p>Yeah that looked like a doosy</p>



<a name="234391980"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234391980" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234391980">(Apr 13 2021 at 20:05)</a>:</h4>
<p>I'll look into it some more later, I think somewhere the opaque type bound isn't being propagated correctly</p>



<a name="234392004"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392004" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392004">(Apr 13 2021 at 20:05)</a>:</h4>
<p>At some point <span class="user-mention" data-user-id="116009">@nikomatsakis</span> too we should discuss <a href="https://github.com/rust-lang/rust/issues/77325">#77325</a></p>



<a name="234392039"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392039" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392039">(Apr 13 2021 at 20:05)</a>:</h4>
<p>ah yes</p>



<a name="234392049"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392049" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392049">(Apr 13 2021 at 20:05)</a>:</h4>
<p>I saw you took on reviewer load for that</p>



<a name="234392153"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392153" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392153">(Apr 13 2021 at 20:06)</a>:</h4>
<p>Yeah, it's been there for a bit and I can either just try to dig through the code myself or spend some time with you going through it</p>



<a name="234392181"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392181" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392181">(Apr 13 2021 at 20:06)</a>:</h4>
<p>I/we should make a list of PRs/things to discuss</p>



<a name="234392211"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392211" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392211">(Apr 13 2021 at 20:06)</a>:</h4>
<p>I have a list that keeps growing</p>



<a name="234392269"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392269" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392269">(Apr 13 2021 at 20:07)</a>:</h4>
<p>that makes sense</p>



<a name="234392293"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392293" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392293">(Apr 13 2021 at 20:07)</a>:</h4>
<p>I'm curious <span class="user-mention" data-user-id="232957">@Jack Huey</span> if you explored the region change we had talked about (with binder kinds)</p>



<a name="234392371"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392371" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392371">(Apr 13 2021 at 20:08)</a>:</h4>
<p>From yesterday morning? I've been hacking on it for the last half hour or so</p>



<a name="234392410"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392410" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392410">(Apr 13 2021 at 20:08)</a>:</h4>
<p>Looks like this will work</p>



<a name="234392416"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392416" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392416">(Apr 13 2021 at 20:08)</a>:</h4>
<p>do we have plans for today?</p>



<a name="234392444"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392444" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392444">(Apr 13 2021 at 20:08)</a>:</h4>
<p>I'd be interested to talk a bit more about type library</p>



<a name="234392455"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392455" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392455">(Apr 13 2021 at 20:08)</a>:</h4>
<p>Well</p>



<a name="234392482"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392482" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392482">(Apr 13 2021 at 20:08)</a>:</h4>
<p>I was wondering if we should briefly summarize/discuss current state of GATs</p>



<a name="234392501"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392501" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392501">(Apr 13 2021 at 20:08)</a>:</h4>
<p>It's something I think we can really push</p>



<a name="234392511"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392511" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392511">(Apr 13 2021 at 20:09)</a>:</h4>
<p>With the exception of two things</p>



<a name="234392524"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392524" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392524">(Apr 13 2021 at 20:09)</a>:</h4>
<p>1) GATs in trait objects</p>



<a name="234392532"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392532" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392532">(Apr 13 2021 at 20:09)</a>:</h4>
<p>Yes, that was also a bit on my mind-- I want to push impl trait over the finish line</p>



<a name="234392536"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392536" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392536">(Apr 13 2021 at 20:09)</a>:</h4>
<p>2) Diagnostics (PR open)</p>



<a name="234392541"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392541" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392541">(Apr 13 2021 at 20:09)</a>:</h4>
<p><span class="user-mention" data-user-id="124288">@oli</span> is out now for parental leave</p>



<a name="234392664"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392664" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392664">(Apr 13 2021 at 20:10)</a>:</h4>
<p>The diagnostics PR looks nearly done. If the PR author can't pick it back up, I might just do that</p>



<a name="234392686"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392686" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392686">(Apr 13 2021 at 20:10)</a>:</h4>
<p>link to diagnostics PR?</p>



<a name="234392737"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392737" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392737">(Apr 13 2021 at 20:10)</a>:</h4>
<p><a href="https://github.com/rust-lang/rust/issues/82272">#82272</a></p>



<a name="234392749"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392749" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392749">(Apr 13 2021 at 20:11)</a>:</h4>
<p>ah, k</p>



<a name="234392793"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392793" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392793">(Apr 13 2021 at 20:11)</a>:</h4>
<p>I forget, is that <span class="user-mention" data-user-id="328097">@BN</span>?</p>



<a name="234392975"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234392975" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234392975">(Apr 13 2021 at 20:12)</a>:</h4>
<p>yes</p>



<a name="234393034"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393034" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393034">(Apr 13 2021 at 20:13)</a>:</h4>
<p><span class="user-mention silent" data-user-id="232957">Jack Huey</span> <a href="#narrow/stream/144729-wg-traits/topic/meeting.202021-04-13/near/234392524">said</a>:</p>
<blockquote>
<p>1) GATs in trait objects</p>
</blockquote>
<p>remind me about this</p>



<a name="234393043"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393043" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393043">(Apr 13 2021 at 20:13)</a>:</h4>
<p>For trait objects with GATs, the primary FIXME I think is <a href="https://github.com/rust-lang/rust/blob/5c1304205b7bc53a1e9f48cf286a60438351c1ab/compiler/rustc_trait_selection/src/traits/select/confirmation.rs#L464">here</a></p>



<a name="234393050"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393050" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393050">(Apr 13 2021 at 20:13)</a>:</h4>
<p>I think maybe <span class="user-mention" data-user-id="116118">@Matthew Jasper</span> was investigating?</p>



<a name="234393085"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393085" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393085">(Apr 13 2021 at 20:13)</a>:</h4>
<p>Yes, but I've not been very active recently.</p>



<a name="234393087"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393087" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393087">(Apr 13 2021 at 20:13)</a>:</h4>
<p>Yeah, they said they were going to after some NLL work I think? But hasn't gotten to it</p>



<a name="234393171"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393171" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393171">(Apr 13 2021 at 20:14)</a>:</h4>
<p>This is as far as I got: <a href="https://github.com/jackh726/rust/commit/fc45318cc1f348ab82317a652ce40da752d83fe0">https://github.com/jackh726/rust/commit/fc45318cc1f348ab82317a652ce40da752d83fe0</a></p>



<a name="234393209"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393209" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393209">(Apr 13 2021 at 20:14)</a>:</h4>
<p>so</p>



<a name="234393226"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393226" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393226">(Apr 13 2021 at 20:14)</a>:</h4>
<p>(I had to stop playing around with it so thing are commented out)</p>



<a name="234393273"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393273" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393273">(Apr 13 2021 at 20:15)</a>:</h4>
<p>I am wondering about making traits with GATs be "non-dyn-safe"</p>



<a name="234393298"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393298" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393298">(Apr 13 2021 at 20:15)</a>:</h4>
<p>I feel like there are some UI questions we have to address</p>



<a name="234393337"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393337" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393337">(Apr 13 2021 at 20:15)</a>:</h4>
<p>Ah yeah, this also led me down the road of "what are the WF rules around dyn types"</p>



<a name="234393541"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393541" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> BN <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393541">(Apr 13 2021 at 20:17)</a>:</h4>
<p>Hey, sorry for not having fixed the conflicts in the diagnostics pr yet. I can do that this week.</p>



<a name="234393570"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393570" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393570">(Apr 13 2021 at 20:17)</a>:</h4>
<p><span class="user-mention silent" data-user-id="232957">Jack Huey</span> <a href="#narrow/stream/144729-wg-traits/topic/meeting.202021-04-13/near/234393337">said</a>:</p>
<blockquote>
<p>Ah yeah, this also led me down the road of "what are the WF rules around dyn types"</p>
</blockquote>
<p>heh yes</p>



<a name="234393580"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393580" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393580">(Apr 13 2021 at 20:17)</a>:</h4>
<p>I'm sort of hoping to sidestep some of these things</p>



<a name="234393583"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393583" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393583">(Apr 13 2021 at 20:17)</a>:</h4>
<p><span class="user-mention silent" data-user-id="232957">Jack Huey</span> <a href="#narrow/stream/144729-wg-traits/topic/meeting.202021-04-13/near/234393171">said</a>:</p>
<blockquote>
<p>This is as far as I got: <a href="https://github.com/jackh726/rust/commit/fc45318cc1f348ab82317a652ce40da752d83fe0">https://github.com/jackh726/rust/commit/fc45318cc1f348ab82317a652ce40da752d83fe0</a></p>
</blockquote>
<p>Specifically, I tried using a placeholder for the <code>'a</code> (in the added test), but that generates a <code>Self: !0</code> obligation, and then that propagates out of the current obligation</p>



<a name="234393739"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393739" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393739">(Apr 13 2021 at 20:18)</a>:</h4>
<p>(That's also probably not the right way to do it, but I'm not sure exactly)</p>



<a name="234393839"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393839" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393839">(Apr 13 2021 at 20:19)</a>:</h4>
<p>But I was basically thinking that once the diagnostics PR lands and we decide what to do for trait objects (and do implementation work if needed), we remove the "incomplete feature" warning and start to get people to test hard</p>



<a name="234393936"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393936" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393936">(Apr 13 2021 at 20:20)</a>:</h4>
<p>hmm</p>



<a name="234393943"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393943" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393943">(Apr 13 2021 at 20:20)</a>:</h4>
<p>seems reasonable</p>



<a name="234393960"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393960" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393960">(Apr 13 2021 at 20:20)</a>:</h4>
<p>what do you think about making them not dyn safe</p>



<a name="234393977"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234393977" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234393977">(Apr 13 2021 at 20:20)</a>:</h4>
<p>is there a backwards compat concern there</p>



<a name="234394009"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394009" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394009">(Apr 13 2021 at 20:20)</a>:</h4>
<p>I can't think of one</p>



<a name="234394015"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394015" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394015">(Apr 13 2021 at 20:20)</a>:</h4>
<p>I don't think there is</p>



<a name="234394125"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394125" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394125">(Apr 13 2021 at 20:21)</a>:</h4>
<p>Okay, so the implementation work there is just to change the <code>span_fatal</code> into a proper error</p>



<a name="234394158"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394158" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394158">(Apr 13 2021 at 20:21)</a>:</h4>
<p><span class="user-mention silent" data-user-id="232957">Jack Huey</span> <a href="#narrow/stream/144729-wg-traits/topic/meeting.202021-04-13/near/234394125">said</a>:</p>
<blockquote>
<p>Okay, so the implementation work there is just to change the <code>span_fatal</code> into a proper error</p>
</blockquote>
<p>what span-fatal?</p>



<a name="234394179"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394179" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394179">(Apr 13 2021 at 20:21)</a>:</h4>
<p><em>oh</em></p>



<a name="234394183"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394183" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394183">(Apr 13 2021 at 20:21)</a>:</h4>
<div class="codehilite" data-code-language="Rust"><pre><span></span><code><span class="w">               </span><span class="n">tcx</span><span class="p">.</span><span class="n">sess</span><span class="p">.</span><span class="n">span_fatal</span><span class="p">(</span><span class="w"></span>
<span class="w">                    </span><span class="n">obligation</span><span class="p">.</span><span class="n">cause</span><span class="p">.</span><span class="n">span</span><span class="p">,</span><span class="w"></span>
<span class="w">                    </span><span class="s">"generic associated types in trait objects are not supported yet"</span><span class="p">,</span><span class="w"></span>
<span class="w">                </span><span class="p">);</span><span class="w"></span>
</code></pre></div>



<a name="234394194"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394194" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394194">(Apr 13 2021 at 20:22)</a>:</h4>
<p>that one</p>



<a name="234394236"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394236" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394236">(Apr 13 2021 at 20:22)</a>:</h4>
<p>yeah</p>



<a name="234394255"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394255" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394255">(Apr 13 2021 at 20:22)</a>:</h4>
<p>without the duplicated lines :P</p>



<a name="234394317"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394317" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394317">(Apr 13 2021 at 20:22)</a>:</h4>
<p>Okay, if that's what we want to do, then I will do that and make a PR</p>



<a name="234394333"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394333" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394333">(Apr 13 2021 at 20:23)</a>:</h4>
<p>well, I think that's a good step</p>



<a name="234394371"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394371" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394371">(Apr 13 2021 at 20:23)</a>:</h4>
<p>i'm trying to thnk how to capture this whole plan</p>



<a name="234394385"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394385" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394385">(Apr 13 2021 at 20:23)</a>:</h4>
<p>have to pull up those hackmds we had</p>



<a name="234394387"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394387" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394387">(Apr 13 2021 at 20:23)</a>:</h4>
<p>Turns out that object safe GATs are hard to work with anyways</p>



<a name="234394509"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394509" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394509">(Apr 13 2021 at 20:24)</a>:</h4>
<p>But, are we okay with moving to stablization with trait objects with GATs being disallowed?</p>



<a name="234394633"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394633" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394633">(Apr 13 2021 at 20:25)</a>:</h4>
<p>I don't see why not</p>



<a name="234394641"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394641" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394641">(Apr 13 2021 at 20:25)</a>:</h4>
<p>Agreed</p>



<a name="234394792"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394792" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394792">(Apr 13 2021 at 20:26)</a>:</h4>
<p>Okay, then after I finish squashing the last couple fires from the binder refactor (also see <a href="https://github.com/rust-lang/rust/issues/83944">#83944</a>), then I'll work on that next</p>



<a name="234394845"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394845" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394845">(Apr 13 2021 at 20:26)</a>:</h4>
<p>isn't there another bug related to the binder refactor?</p>



<a name="234394875"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394875" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394875">(Apr 13 2021 at 20:26)</a>:</h4>
<p>that is, we worked around the problem, but I feel like you felt there was something wrong still with generators</p>



<a name="234394884"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394884" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394884">(Apr 13 2021 at 20:27)</a>:</h4>
<p>and we never really got into it</p>



<a name="234394974"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394974" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394974">(Apr 13 2021 at 20:27)</a>:</h4>
<p>yes</p>



<a name="234394982"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234394982" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234394982">(Apr 13 2021 at 20:27)</a>:</h4>
<p>That's the other fire</p>



<a name="234395109"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395109" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395109">(Apr 13 2021 at 20:28)</a>:</h4>
<p>It happens when a type that contains unused binders ends up in a generator witness</p>



<a name="234395184"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395184" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395184">(Apr 13 2021 at 20:29)</a>:</h4>
<p>I really am just most worried that about this same type of problem occurring elsewhere</p>



<a name="234395299"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395299" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395299">(Apr 13 2021 at 20:30)</a>:</h4>
<p>The <em>simplest</em> solution is to force the erasure of all binders when comparing, but that's not really right</p>



<a name="234395323"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395323" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395323">(Apr 13 2021 at 20:30)</a>:</h4>
<p>do you want to talk about it in more detail?</p>



<a name="234395347"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395347" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395347">(Apr 13 2021 at 20:30)</a>:</h4>
<p>it's not obvious why unused binders should cause a problem</p>



<a name="234395377"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395377" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395377">(Apr 13 2021 at 20:30)</a>:</h4>
<p>Sure, I can type out a bit</p>



<a name="234395452"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395452" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395452">(Apr 13 2021 at 20:31)</a>:</h4>
<p>So, imagine we have <code>Box&lt;dyn for&lt;'a&gt; Future&lt;Output = ()&gt;&gt;</code> as a return type for a <code>Fn</code> <code>F</code></p>



<a name="234395499"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395499" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395499">(Apr 13 2021 at 20:31)</a>:</h4>
<p>If we call that function in a generator/<code>async</code> fn, then we end up with that type in the generator witness</p>



<a name="234395534"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395534" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395534">(Apr 13 2021 at 20:32)</a>:</h4>
<p>Now, let me remember which way around this is</p>



<a name="234395734"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395734" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395734">(Apr 13 2021 at 20:33)</a>:</h4>
<p>Right, so</p>



<a name="234395811"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395811" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395811">(Apr 13 2021 at 20:33)</a>:</h4>
<p>When inserting that type into the generator witness, we call <code>erase_regions</code></p>



<a name="234395895"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395895" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395895">(Apr 13 2021 at 20:34)</a>:</h4>
<p>which recursive calls <code>anonymize_late_bound_regions</code> and then replaces non-bound regions with <code>ReErased</code></p>



<a name="234395985"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234395985" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234395985">(Apr 13 2021 at 20:34)</a>:</h4>
<p>Importantly, <code>anonymize_late_bound_regions</code> as-is, remakes the bound vars based on <em>all</em> the regions contained</p>



<a name="234396004"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396004" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396004">(Apr 13 2021 at 20:34)</a>:</h4>
<p>Since every region gets a new anon index</p>



<a name="234396040"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396040" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396040">(Apr 13 2021 at 20:35)</a>:</h4>
<p><code>Future&lt;Output = ()&gt;</code> has not bound regions, so the bound vars become <code>[]</code></p>



<a name="234396096"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396096" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396096">(Apr 13 2021 at 20:35)</a>:</h4>
<p>And the type that gets inserted into the witness is <code>Box&lt;dyn Future&lt;Output = ()&gt;&gt;</code></p>



<a name="234396118"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396118" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396118">(Apr 13 2021 at 20:35)</a>:</h4>
<p>The other half I haven't tracked down exactly</p>



<a name="234396195"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396195" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396195">(Apr 13 2021 at 20:36)</a>:</h4>
<p>right</p>



<a name="234396200"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396200" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396200">(Apr 13 2021 at 20:36)</a>:</h4>
<p>so that part seems fine</p>



<a name="234396238"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396238" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396238">(Apr 13 2021 at 20:36)</a>:</h4>
<p>what's confusing to me is why we can't just erase the regions from the type on the other end</p>



<a name="234396257"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396257" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396257">(Apr 13 2021 at 20:36)</a>:</h4>
<p>But essentially what's happening is that instead of <code>erase_regions</code>, <code>erase_late_bound_regions</code> is called, which just changes all the bound regions to <code>ReErased</code></p>



<a name="234396285"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396285" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396285">(Apr 13 2021 at 20:36)</a>:</h4>
<p>but <em>doesn't</em> remake the bound vars</p>



<a name="234396363"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396363" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396363">(Apr 13 2021 at 20:37)</a>:</h4>
<p>So the "local declaration" ends up being <code>Box&lt;dyn for&lt;'a&gt; Future&lt;Output = ()&gt;&gt;</code></p>



<a name="234396451"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396451" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396451">(Apr 13 2021 at 20:37)</a>:</h4>
<p>Now, I <em>tried</em> to just make <code>erase_late_bound_regions</code> remake the bound vars. It might have been a pretty naive attempt, but it didn't work</p>



<a name="234396459"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396459" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396459">(Apr 13 2021 at 20:38)</a>:</h4>
<p><span class="user-mention silent" data-user-id="232957">Jack Huey</span> <a href="#narrow/stream/144729-wg-traits/topic/meeting.202021-04-13/near/234396257">said</a>:</p>
<blockquote>
<p>But essentially what's happening is that instead of <code>erase_regions</code>, <code>erase_late_bound_regions</code> is called, which just changes all the bound regions to <code>ReErased</code></p>
</blockquote>
<p>do you remember where this is in the code?</p>



<a name="234396539"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396539" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396539">(Apr 13 2021 at 20:38)</a>:</h4>
<p>Well, like I said, I haven't tracked that down <em>exactly</em></p>



<a name="234396543"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396543" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396543">(Apr 13 2021 at 20:38)</a>:</h4>
<p>But</p>



<a name="234396586"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396586" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396586">(Apr 13 2021 at 20:38)</a>:</h4>
<p>uh give me a sec</p>



<a name="234396685"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396685" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396685">(Apr 13 2021 at 20:39)</a>:</h4>
<p>It <em>might</em> be in <code>local_decls_for_sig</code></p>



<a name="234396705"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396705" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396705">(Apr 13 2021 at 20:39)</a>:</h4>
<p>In <code>shim.rs</code></p>



<a name="234396733"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396733" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396733">(Apr 13 2021 at 20:39)</a>:</h4>
<p>(<code>rustc_mir::shim</code>)</p>



<a name="234396762"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396762" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396762">(Apr 13 2021 at 20:39)</a>:</h4>
<p>err no</p>



<a name="234396774"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396774" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396774">(Apr 13 2021 at 20:39)</a>:</h4>
<p>Things get erased <em>before</em> that</p>



<a name="234396932"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396932" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396932">(Apr 13 2021 at 20:41)</a>:</h4>
<p>hmm</p>



<a name="234396956"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234396956" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234396956">(Apr 13 2021 at 20:41)</a>:</h4>
<p>Maybe <a href="https://github.com/rust-lang/rust/blob/132b4e5d167b7e622fcc11fa2b67b931105b4de1/compiler/rustc_mir/src/shim.rs#L679">here</a></p>



<a name="234397005"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397005" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397005">(Apr 13 2021 at 20:41)</a>:</h4>
<p>Part of the problem is I had basically never seen this code before trying to debug this issue, so I have no clue what the machinery here looks like</p>



<a name="234397142"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397142" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397142">(Apr 13 2021 at 20:42)</a>:</h4>
<p>ok</p>



<a name="234397182"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397182" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397182">(Apr 13 2021 at 20:42)</a>:</h4>
<p>let me find my check out</p>



<a name="234397214"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397214" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397214">(Apr 13 2021 at 20:43)</a>:</h4>
<p>I don't know if I need to keep the non-bound regions as they are in this code</p>



<a name="234397244"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397244" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397244">(Apr 13 2021 at 20:43)</a>:</h4>
<p>Or if I can, say, call <code>erase_regions</code> on <code>sig</code> <em>before</em> <code>erase_late_bound_regions</code></p>



<a name="234397267"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397267" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397267">(Apr 13 2021 at 20:43)</a>:</h4>
<p>I just have to look more into it and haven't yet</p>



<a name="234397313"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397313" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397313">(Apr 13 2021 at 20:44)</a>:</h4>
<p>remind me your branch, <span class="user-mention" data-user-id="232957">@Jack Huey</span></p>



<a name="234397409"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397409" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397409">(Apr 13 2021 at 20:44)</a>:</h4>
<p>uh</p>



<a name="234397429"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397429" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397429">(Apr 13 2021 at 20:44)</a>:</h4>
<p>I don't know if I have a branch with any of these changes</p>



<a name="234397453"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397453" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397453">(Apr 13 2021 at 20:44)</a>:</h4>
<p>The changes I had landed already</p>



<a name="234397553"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397553" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397553">(Apr 13 2021 at 20:45)</a>:</h4>
<p>I thought you had some kind of branch that added .. something</p>



<a name="234397582"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397582" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397582">(Apr 13 2021 at 20:45)</a>:</h4>
<p>but maybe I'm just thinking of the branch that landed</p>



<a name="234397602"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397602" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397602">(Apr 13 2021 at 20:45)</a>:</h4>
<p>commit <a href="https://github.com/rust-lang/rust/commit/c1dc0b7bbc239290388d2365c6d0b282e299bdbc">c1dc0b7bbc239290388d2365c6d0b282e299bdbc</a> (HEAD -&gt; binder-refactor-fix)<br>
Author: Niko Matsakis &lt;<a href="mailto:niko@alum.mit.edu">niko@alum.mit.edu</a>&gt;<br>
Date:   Thu Apr 8 10:56:03 2021 -0400</p>
<div class="codehilite"><pre><span></span><code>add comments
</code></pre></div>

<p>commit <a href="https://github.com/rust-lang/rust/commit/1a14315975224951bc993455783678154afade09">1a14315975224951bc993455783678154afade09</a><br>
Author: Jack Huey &lt;<a href="mailto:jack.huey@umassmed.edu">jack.huey@umassmed.edu</a>&gt;<br>
Date:   Mon Apr 5 00:10:09 2021 -0400</p>
<div class="codehilite"><pre><span></span><code>Don&#39;t concatenate binders across types
</code></pre></div>



<a name="234397613"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397613" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397613">(Apr 13 2021 at 20:46)</a>:</h4>
<p>that's my current git log :)</p>



<a name="234397692"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397692" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397692">(Apr 13 2021 at 20:46)</a>:</h4>
<p>I guess I can reset to rust-lang/master?</p>



<a name="234397696"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397696" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397696">(Apr 13 2021 at 20:46)</a>:</h4>
<p>oh that branch</p>



<a name="234397716"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397716" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397716">(Apr 13 2021 at 20:46)</a>:</h4>
<p>I wanted to run this code and see problems</p>



<a name="234397796"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397796" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397796">(Apr 13 2021 at 20:47)</a>:</h4>
<p>I mean, best bet is just to modify the <a href="https://github.com/rust-lang/rust/issues/83737">#83737</a> test on master</p>



<a name="234397815"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234397815" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234397815">(Apr 13 2021 at 20:47)</a>:</h4>
<p>to add the <code>for&lt;'a&gt;</code></p>



<a name="234398046"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398046" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398046">(Apr 13 2021 at 20:48)</a>:</h4>
<p>ok</p>



<a name="234398078"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398078" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398078">(Apr 13 2021 at 20:48)</a>:</h4>
<p>so, to back up a second, I'm thinking about how to get organized overall</p>



<a name="234398089"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398089" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398089">(Apr 13 2021 at 20:48)</a>:</h4>
<p>it seems like we have a few things going on</p>



<a name="234398110"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398110" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398110">(Apr 13 2021 at 20:49)</a>:</h4>
<p><em>a few</em></p>



<a name="234398116"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398116" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398116">(Apr 13 2021 at 20:49)</a>:</h4>
<ul>
<li>chalk-ty extraction and integration -- should check back in on this</li>
</ul>



<a name="234398128"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398128" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398128">(Apr 13 2021 at 20:49)</a>:</h4>
<ul>
<li>named impl Trait stabilization</li>
</ul>



<a name="234398134"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398134" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398134">(Apr 13 2021 at 20:49)</a>:</h4>
<ul>
<li>gat stabilization</li>
</ul>



<a name="234398170"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398170" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398170">(Apr 13 2021 at 20:49)</a>:</h4>
<ul>
<li>Chalk closure bug</li>
</ul>



<a name="234398188"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398188" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398188">(Apr 13 2021 at 20:49)</a>:</h4>
<p>ah yeah I keep ignoring that</p>



<a name="234398202"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398202" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398202">(Apr 13 2021 at 20:49)</a>:</h4>
<p>you're going to have to explain that to me at some point :)</p>



<a name="234398217"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398217" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398217">(Apr 13 2021 at 20:50)</a>:</h4>
<p>Yeah, at some point</p>



<a name="234398297"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398297" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398297">(Apr 13 2021 at 20:50)</a>:</h4>
<p>Some many things that we basically spend like an hour just going through the problem lol</p>



<a name="234398796"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398796" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398796">(Apr 13 2021 at 20:54)</a>:</h4>
<p>ok well, I will try to reproduce the problem, we can dig into that in a future session. I'd like us to collect all the ongoing things into more a project board or something, because it's hard to stay organized :)</p>



<a name="234398821"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398821" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398821">(Apr 13 2021 at 20:54)</a>:</h4>
<p>I just have to decide which structure i like :P</p>



<a name="234398840"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398840" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398840">(Apr 13 2021 at 20:54)</a>:</h4>
<p>Yeah, kind of what I was saying earlier</p>



<a name="234398865"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234398865" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234398865">(Apr 13 2021 at 20:54)</a>:</h4>
<p>Also to add to that list</p>
<ul>
<li>Obligations PR (<a href="https://github.com/rust-lang/rust/issues/77325">#77325</a>)</li>
</ul>



<a name="234399417"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234399417" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234399417">(Apr 13 2021 at 20:58)</a>:</h4>
<p>Also <span class="user-mention" data-user-id="116009">@nikomatsakis</span> just pushed the changes we discussed yesterday: <a href="https://github.com/jackh726/rust/tree/binder-refactor-fix">https://github.com/jackh726/rust/tree/binder-refactor-fix</a></p>



<a name="234399974"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234399974" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234399974">(Apr 13 2021 at 21:01)</a>:</h4>
<p>I am reminded that I think this can subsume the "trait-ref-hack"</p>



<a name="234401751"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234401751" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234401751">(Apr 13 2021 at 21:07)</a>:</h4>
<p>Yes, I can attempt to do that</p>



<a name="234401834"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202021-04-13/near/234401834" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202021-04-13.html#234401834">(Apr 13 2021 at 21:08)</a>:</h4>
<p>Wanted to get your thoughts. Mostly if this is what you were expecting</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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